Exploring The Secrets Of Underground New York

All above-ground metropolises harbor shadow cities beneath. A New York Times reporter spent five days on a subterranean urban hiking expedition, spelunking through NYC’s labyrinthine sewer system. His colorful travel journal details encounters with wildlife and “mole people.” Here’s how to go on an invigorating adventure into the unknown, without leaving city limits:

Tuesday, 12:36 a.m.Exterior Street, the Bronx

We inspect our exit point — a manhole in the middle of the road. Will Hunt, a bespectacled 26-year-old who is writing a book about the underground (“The last frontier,” he says, “in an over-mapped, Google-Earthed world.”) will serve as our spotter. Will’s job is to watch for traffic: ascending from the hole, we do not wish to be hit by a car. We are to communicate by walkie-talkie. Will ties a long pink ribbon to the inside of the manhole cover. Dangling downward, this will be our signal we have reached the end.

1:20 a.m.Van Cortlandt Park, the Bronx

Down we go by way of sewer pipe, joined now by Andrew Wonder, a shaggy former film student making a documentary about Steve. The change is stark, immediate: darkness, shin-high water, a dull ammoniac funk. My eyes adjust, and I see an endless tunnel, rounded, eight feet high and made of faded brick. The floor is scummy and perilous to walk on. Within seconds, Steve, Erling and Andrew rip their waders: they’re taking on water. We nonetheless progress and, after 50 feet, the entrance disappears. Forgot how much I hate enclosed spaces.

1:48 a.m.Bronx sewers

Amazing. The sounds down here are even more impressive than the sights and smells: the Niagara-like crash of water spilling in from side drains; the rumble of the subway; the guh-DUNK! of cars hitting manhole covers overhead, like two jabs on a heavy bag. Steve says we’re only 12 feet beneath the surface, but it feels far deeper. The familiar world is gone: only sewage now, the press of surrounding earth, the anxious dance of headlamps on the water. Every 100 feet or so, an archway appears and we can see a parallel channel gurgling beside us with a coffee-colored murk. I shine my headlamp down and watch a condom and gooey scraps of toilet paper float by. I check the air meter constantly: no trace of gas, and the oxygen level is a healthy 20.9 percent. I ask Steve how he navigates down here; he laughs. “Hey, Erling,” he calls out, “you’re taking care of the navigation, right?” Funny.

December, 2007. The distant Alps are covered in snow. Small flakes swirl in the wind, dancing around red clay statues of muscular giants and voluptuous goddesses, reminiscent of Egypt. Most prominent...